How to Make a White Hole in Your Kitchen Sink

[n2doc]

By Lisa Grossman October 14, 2010 | 1:13 pm | Categories: Physics


That ring of water in your kitchen sink is actually a model white hole. For the first time, scientists have shown experimentally that liquid flowing from a tap embodies the same physics as the time-reversed equivalent of black holes.

When a stream of tap water hits the flat surface of the sink, it spreads out into a thin disc bounded by a raised lip, called the hydraulic jump. Physicists’ puzzlement with this jump dates back to Lord Rayleigh in 1914. More recently, physicists have suggested that, if the water waves inside the disc move faster than the waves outside, the jump could serve as an analogue event horizon. Water can approach the ring from outside, but it can’t get in.

“The jump would therefore constitute a one-directional membrane or white hole,” wrote physicist Gil Jannes and Germain Rousseaux of the University of Nice Sophia Antipolis in France and colleagues in a study on ArXiv Oct. 8. “Surface waves outside the jump cannot penetrate in the inner region; they are trapped outside in precisely the same sense as light is trapped inside a black hole.”

The analogy is not just surface-deep. The math describing both situations is exactly equivalent. But so far, no one had been able to prove experimentally that what’s going on in the kitchen sink really represents a white hole.



Read More http://www.wired.com/wiredscience/2010/10/kitchen-sink-white-hole/

[catbyte]

1. Huh?

I'm ashamed to say it, but I think I'll have to read that article twice! My brain feels scrambled. :)

:hide:

[AlecBGreen]

2. a kitchen sink is a model of a black hole in reverse

aka a white hole.

In a white hole (the sink) water flows down & spreads out. There is a lip around the edge that marks the border. INSIDE the border, water can only flow OUTWARDS.

A black hole is just like this model but in reverse. Things flow INWARD toward the stream of water. Past the bump, they cannot travel back out. They then reach the stream of water and rush up to the faucet.

[MineralMan]

3. Too cool! A model that's fairly easy to understand.

I love science!

[PVnRT]

4. Fuck Lord Rayleigh and his complex mathematics

You made fluid mechanics a living hell, prick.

[intaglio]

6. There speaks an Engineer or Physicist

probably ... but you still know more than me

[jayfish]

5. I've just created a black hole.

Complete with a relativistic jet. ;)

[hunter]

7. Maybe human beings experience time backwards...

...and all that stuff we see falling into a black hole is actually spewing out.

[atomic-fly]

8. interesting...

I always thought galaxies looked like they were draining into something.

[Kaleva]

9. Wrote about something like that in the Religion topic forum

That prophets aren't telling us what will happen in the future. They are telling us what happened in the past.

[NBachers]

10. Yup- and we're all falling back toward it in time and space

[lonestarnot]

11. Interesting!